With most of the broken glass swept away, Mo Trattles is sitting by the computer in her office high above the Salsa café and tapas bar going through the CCTV footage from Sunday afternoon.

Frame by frame, image by image, she tracks through the riot on the streets around St James' Park that followed the Newcastle United-Sunderland derby.

"This is why what happened [on Sunday] will turn out to be just a blip," she says. "Things like CCTV and the cameras on everyone's mobile will see to that. Big Brother may be looking at us too much some times, but at times like this it's great.

"Within minutes of things kicking off material like this was all over the social media sites like YouTube. And the point is that all of us can see these yobs as clear as day, and someone, somewhere will recognise them."

Over the coming weeks, Northumbria police will be analysing thousands of hours of footage similar to that recorded by Trattles. This will be supplemented by endless photographs and videos recorded by myriad eye-witnesses.

Police regard such evidence as so central to their investigation of the riot on Sunday that they have already appealed for those with footage to come forward. It is the key tool available to them to tackle football violence; a marked advance from the 1980s.

Chief Superintendent Steve Neill, who has organised the policing of Tyne-Wear derbies for 20 years, said: "We'd very much like people to come to us or to Crimestoppers with their footage. It's important we deal with these individuals and put them before the courts."

Three police officers were injured in the clashes. So far, 29 people have been arrested, but police expect the numbers to multiply as they identify those involved.

One of those already held is the man alleged to have punched a police horse outside the ground. He has since been released on bail.

Although the small corner of the riot witnessed by Trattles was a sideshow compared to the main event a few hundred yards up the hill towards St James' Park, she was still alarmed enough to pull down the steel shutter over her front door and shepherd customers away from the windows.

Twenty-four hours later she is replaying the lead role played by one man in a green parka-style jacket.

He is seen entering the fray at 2.43.02pm, delving into the bar's blue bin in the alleyway outside and taking out four bottles. He throws one within a couple of seconds and then heads off towards the police ranks with the rest.

Less than a minute later he is back, this time dragging the bin away so he and others can use it as a portable arsenal.

"I've seen the bin on fire on YouTube, and I bet you there's footage of the same lad. It's so crazy. Does he really think he'll get away with it?"

Trattles doubts that the riot was organised. "It just looks like idiot kids coming along to have a scrap. There were some genuine Newcastle fans in the bar at the time it kicked off, and all they were doing was having a quiet drink. They were appalled at what went on."

There was a similar sense of revulsion at The Strawberry, the pub across the road from the Newcastle United merchandise store.

"We'd been open from 9am and the first thing we knew about it was when the news came on at 7pm," said licensee Caroline Armstrong. "The place was heaving with Newcastle fans and they were all just shocked and stunned.

"There have been bits of trouble before – like when Keegan left the second time, and when the name of the stadium was changed from St James' – but nothing like this.

"When you see the thugs on TV most of them seem to be quite young – school kids out for trouble.

"The good thing is that these days it's so much easier to name and shame them."

Morten Pedersen, 42, a Newcastle fan on a four-day "pilgrimage" from his home in Stavanger, Norway, was sanguine about the riot.

"It did worry me, but I wasn't too surprised because there is a history between the two clubs.

"I don't think it means Britain is heading back to the 70s and 80s when football violence was everywhere. It was just a one-off. I will be back. I just hope that next time we don't lose 3-0 at home."